Effect of motion on cardiac SPECT imaging: recognition and motion correction.

Cardiac motion is likely to occur during long single photon emission computed tomography acquisitions or if there is considerable patient discomfort. Motion causes data misregistration and may decrease the accuracy of interpretation of cardiac single photon emission computed tomography by introducing image artifacts, such as smearing of counts around the ventricle ("hurricane sign"), distortion and discontinuities of the ventricular walls, nonanatomic defects, and hot spots. Although motion should be avoided during data acquisition, motion correction techniques have been developed to allow for manual or semiautomated compensation of cardiac displacement and should be used when motion cannot be eliminated.